AIOHAWKS. [NORTH AUERICAN lentANs.] MOIDOfnE. [aloem] MOW, a French word, having the meaning of clouded, mottled, or watered, is applied as a name to two different kinds of effects produced in manufactures : the one on metals, the other on textile goods.
The moire metal/Nee, first introduced by the French, presents a singular beauty and richness of appearance, something like the crystal lised frost on a window in winter. The substance is formed of tinned iron plate, while the surface effect is due to the chemical action of acids. The moire appears to be formed by the action of the tin on the iron at the point of contact ; and the purpose of the acid is rather to render this visible than actually to produce-it. Tin plate consists of a piece of sheet iron coated with a thin layer of tin while the latter is iu a molten state ; and the art of preparing the moire metallique consists in removing all except an extremely thin film of this tin, without really exposing the iron in any part. Various acids and mixtures of acids will effect this, but the one usually employed is diluted nitro muriatie acid. The plate of tinned iron, atter being slightly heated, is washed with the acid. As soon as the workman sees the moire develope itself, he plunges the sheet into cold water, and gently washes off the acid and dissolved tin with a feather or a bit of cotton wool. The time necessary to produce this action varies from one to ten minutes, according to the strength of the acid and the heat of the plate. When the moire has been properly developed, and the acid and tie removed, the plate is carefully dried, and the variegated surface protected by a coating of varnish ; if the varnish be white, a silvery or pearly moire is produced; if coloured, richly diversified tints are obtained. A modi fied kind of moire metallique is produced by the action of heat without acids. The plate of tinned iron is exposed to such a temperature as will melt the tin; and varied effects are produced according to the mode and rapidity of cooling. If cooled gradually, the surface presents a certain kind of moire or crystallisation; if suddenly cooled by plunging in cold water, the weird is different in character ; if unequally cooled by water being sprinkled on certain parts, or wind blown upon them, the effect undergoes still further variations. So, on the other hand, if
the heating of the plate can be so managed as to be unequal at different parts, a variation in the moire results ; and attempts are sometimes made to give a definite pattern to these irregularities. Nobili has pro duced some very beautiful metalloehromes, or richly coloured spots on surfaces of steel, silver, and other metals; and ler. Gassiot has varied the effects of surface thus produced ; but the work is one kind of electro-metallurgy, and the effect bears little resemblance in appearance to moire metallique. As a question of mere fashion, the last-named material is not now used so much as it was twenty years ago, when kaleidoscopes and ornamental boxes were covered with it ; but it never theless remains among the list of articles available for decorative manufactures.
The moire effect on textile goods, generally called moire antique, is produced mostly in broad silks for ladies' dresses. It is a superior kind of that which is known as watering in silk ; and the moireere, or calcuderers, endeavour to keep secret the exact mode in which it is performed. The moire, clouding, or watering, is not produced io the dyeing, the spinning, or the weaving ; it is a sort of calendering or pressing between two cylinders. By using cylinders hot or cold, em bossed or plain, by sprinkling the silk or not with water, and by folding two layers of silk over each other either rectangularly or diagon ally, various kinds and degrees of moire may be produced ; those threads, whether of warp or weft, which happen to be most pressed, receive most gloss; some of them become flattened ; and the reflection from their surface is glossy or otherwise according to the angle at which they are viewed. Thus a very brilliant play of light and shade is produced, although all the threads may he of one colour throughout.